The invention relates to apparatus useful in laparoscopic surgery, and particularly to a device enabling tissue to be withdrawn from a body cavity using laparoscopic surgical tools while maintaining gas pressure within the body cavity.
Laparoscopic surgery commonly requires that one or more small openings be made through the tissues of a patient to enable the insertion of laparoscopic surgical instruments. Commonly, the body cavity (the abdomen, the knee capsule, etc.) in which laparoscopic surgery is to be performed is first inflated with a gas such as CO2 to provide an open, inflated area within which the surgical instruments may be manipulated. A catheter may be provided through the tissue wall bounding the body cavity, and it is through the catheter that the surgical instruments are introduced into the body cavity. Because the body cavity is pressurized, there is a tendency for the pressurizing gas within the body cavity to escape outwardly through the catheter, thereby deflating the cavity. To counter this problem, a number of devices have been proposed to provide a pressure seal within the catheter, but yet enable laparoscopic instruments to be passed inwardly and outwardly of the body cavity through the catheter. One such seal is shown in Mollenauer, et al., U.S. Pat. No. 5,634,937. Another is shown in published UK Patent Application GB 2 275 420 (Gaunt, et al.), and yet another is shown in PCT Intemational Publication No. WO 94/22357 (Yoon). The sealing devices described in the above references by and large relate to inflatable, donut-like devices, through the center of which laparoscopic instruments may be passed.
Although those portions of laparoscopic instruments that are introduced through a cannula into a body cavity are routinely fairly uniform in size, and thus can be introduced and withdrawn from the catheter with some ease, a problem arises when instruments with diameters much larger or smaller that usual are to be introduced into the body cavity, or particularly when pieces of tissue are severed within the body cavity and are to be withdrawn through the catheter without significant loss of pressure in the body cavity. Particularly in the latter case, the tissue sample may not easily fit through the gas seal that is provided, and in this instance, the tissue sample may in fact have to be painstakingly severed into small pieces in order to be successfully removed. If a large tissue sample is removed with some force, then the seal mechanism may be damaged, resulting in a loss of pressure within the body cavity with easily foreseeable medical problems.
It would be desirable to provide a laparoscopic access apparatus that would maintain a seal against the escape of gas from within a body cavity, that would enable large tissue samples to be withdrawn through the catheter without damage to the pressure seal, and that would also adapt to a variety of instrument sizes and configurations that are to be passed into and out of the catheter.
I have found that a suitable gas seal may be made from a film of generally tubular flexible material carried in laparoscopic access catheter, the film at one side of the catheter being stretched tautly, and the film elsewhere in the catheter remaining baggy and loose. The outer surface of the baggy film portion defines, with the catheter walls, an inflatable cavity between the catheter and the sleeve, and the inner surface of the sleeve defines a channel leading through the catheter. The sleeve is joined at its distal and proximal ends to the catheter adjacent its distal and proximal ends.
The taut configuration of the flexible sleeve on one side of the catheter, together with the loose, baggy nature of the sleeve elsewhere in the catheter and the sealing of the sleeve at its ends to the catheter, enable the baggy portion of the sleeve to readily deform toward the catheter walls without ripping or tearing to allow passage through the channel of large objects such as tissue specimens from within a body cavity within which laparoscopic surgery occurs. The apparatus includes a gas port positioned to enable gas under pressure from within the body cavity to enter the cavity between the sleeve and catheter to thereby collapse the sleeve and seal the channel defined by the sleeve.
In its sealed configuration, the sleeve will readily accept the passage of laparoscopic instruments passed through the catheter into the body cavity, the sleeve collapsing onto and conforming to the instruments to maintain the gas seal. As large tissue specimens are removed through the catheter, the sleeve will similarly collapse about the tissue specimen, such that as the specimen is drawn outwardly, the channel within the sleeve will enlarge to accept the specimen, the sleeve collapsing against itself beneath the specimen as the specimen passes to thereby maintain the gas seal.
Thus, in one embodiment, the invention provides a laparoscopic access apparatus enabling the removal of tissue or other debris from a surgical site. The apparatus comprises a catheter having a longitudinal axis. A flexible sleeve having distal and proximal ends is carried within the catheter, the sleeve forming an inner channel through which laparoscopic surgical instruments may be passed. The sleeve is mounted with axial tautness along one side of the catheter, and has a loose, baggy portion elsewhere in the catheter defining an inflatable cavity between the catheter and sleeve. The apparatus includes a gas port positioned to enable gas under pressure to enter the cavity adjacent to the distal end of the sleeve to thereby collapse the sleeve and seal the channel.